I have had a Wheaten and they are amazing dogs, but need a lot of coat care as they don’t shed, so the fur continually grows and easily tangles if it’s not well managed, which is painful for the dog and can lead to health issues.
They are a very fun breed, energetic, with a real zest for life, but it is worth remembering they are still terriers and can be very stubborn. They need a lot of training and socialisation as pups. Mine was an absolute superstar, but she went to two different puppy classes, had extensive training and socialisation when she was young and we did lots of different dog-sports/activities together.
I would be worried about any breeder that has pups available ‘off the shelf’ as it were. Decent breeders vet potential homes rigorously from the first phone-call, operate a waiting list for their pups and only breed when they know they have homes for the whole litter. They will also insist on a contract, often involving breeding restrictions and a requirement that the pup is returned to them if you every need to rehome for some reason. Somewhere that has pups readily available is highly likely to be a puppy farm or backyard breeder.
If you are really interested in a Wheaten I would contact the breed club in whatever country you are in, find out more about them and arrange to meet them in person. This is the UK one.
Really, to choose a breed you should be considering what you can realistically manage to give the dog in terms of training, coat care, exercise etc, then researching breeds that would work well for your family. You could then start approaching breeders or the breed club of the ones you think could work, meet some of the dogs and narrow it down to which feels like the right fit. You would then probably need to go on a a waiting list, which will vary in length dependent on breed. (I waited 18 months for my Wheaten.)
A dog is a 10-15 year commitment, so it’s worth putting in the effort to make sure you get the right dog for your family, which is healthy and has had the best start in life.
An alternative would be to go to your local rescue shelter and have a chat with them. They may be able to suggest dogs in their care that might be a good match for your family.